A valve timing controller controls a rotation phase of a driven rotor that rotates with a camshaft relative to a driving rotor that rotates with a crankshaft using planet movement of a planet gear.
JP 4360426 B (US 2009/0017952 A1) describes a valve timing controller in which a driving side planet external gear part and a driven side planet external gear part of a planet gear mesh with a driving side solar internal gear part of a driving rotor and a driven side solar internal gear part of a driven rotor, respectively, in the eccentric state. The valve timing controller is suitably mounted to an internal combustion engine, for example, in a narrow space of a vehicle, since a large reduction ratio can be obtained with the downsized structure.
In JP 4360426 B, the planet gear and the driving rotor are supported by a planet bearing and a solar bearing respectively from an inner side in the radial direction, and a planet carrier is supported by the planet bearing and the solar bearing from an outer side in the radial direction. The planet gear can smoothly have planet movement according to a relative rotation of the planet carrier relative to the driving side solar internal gear part of the driving rotor, so it is possible to improve the control responsivity of the valve timing according to the rotation phase.
In JP 4360426 B, an elastic component is interposed between the planet carrier and the planet bearing, thereby biasing the planet gear to the eccentric side through the planet bearing relative to the driving rotor and the driven rotor. Thus, abnormal noise and wear are restricted at an engagement portion between the driving side solar internal gear part and the driving side planet external gear part and an engagement portion between the driven side solar internal gear part and the driven side planet external gear part.
In JP 4360426 B, the planet bearing has double rows of spherical rolling elements interposed between an outer wheel that supports the planet gear from a radially inner side and an inner wheel that supports the planet carrier from a radially outer side. Moreover, the solar bearing similarly has double rows of spherical rolling elements interposed between an outer wheel that supports the driving rotor from a radially inner side and an inner wheel that supports the planet carrier from a radially outer side.